1. Field of the Invention
The invention relates to hot melt adhesives and somewhat more particularly to a method of producing foamable hot melt adhesives, the resultant product and the use thereof.
2. Prior Art
Hot melt adhesives are generally known and described, for example, in U.S. Pat. No. 4,018,733 (corresponding to German OS No. 2,347,799), which is incorporated herein by reference. A disadvantage of these hot-melt adhesives is that they cannot penetrate into relatively small apertures, cracks and the like. The prior art described in U.S. Pat. No. 4,018,733 generally comprises homopolymers or copolymers of, for example, polyethylene, polyamide and others, which in part also carry acidic or basic groups and also contain adhesion-promoting agents.
Properties exhibited by hot-melt adhesives and their chemical compositions generally always greatly depend on the environment of use. In principle, any desired thermoplastic can be utilized as a hot-melt adhesive. General information concerning hot-melt adhesives is available in the literature, for example Roempp, Chemielexikon.